sched_setaffinity.c 2.6 KB

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  1. /* Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. The GNU C Library is free software; you can redistribute it and/or
  4. modify it under the terms of the GNU Lesser General Public
  5. License as published by the Free Software Foundation; either
  6. version 2.1 of the License, or (at your option) any later version.
  7. The GNU C Library is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10. Lesser General Public License for more details.
  11. You should have received a copy of the GNU Lesser General Public
  12. License along with the GNU C Library; if not, write to the Free
  13. Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  14. 02111-1307 USA. */
  15. #include <features.h>
  16. #ifdef __USE_GNU
  17. #include <sched.h>
  18. #include <sys/types.h>
  19. #include <sys/syscall.h>
  20. #include <string.h>
  21. #include <unistd.h>
  22. #include <sys/param.h>
  23. #include <alloca.h>
  24. #if defined __NR_sched_setaffinity
  25. #define __NR___syscall_sched_setaffinity __NR_sched_setaffinity
  26. static __inline__ _syscall3(int, __syscall_sched_setaffinity, __kernel_pid_t, pid,
  27. size_t, cpusetsize, cpu_set_t *, cpuset)
  28. static size_t __kernel_cpumask_size;
  29. int sched_setaffinity(pid_t pid, size_t cpusetsize, const cpu_set_t *cpuset)
  30. {
  31. size_t cnt;
  32. if (unlikely (__kernel_cpumask_size == 0)) {
  33. INTERNAL_SYSCALL_DECL (err);
  34. int res;
  35. size_t psize = 128;
  36. void *p = alloca (psize);
  37. while (res = INTERNAL_SYSCALL (sched_getaffinity, err, 3, getpid (),
  38. psize, p),
  39. INTERNAL_SYSCALL_ERROR_P (res, err)
  40. && INTERNAL_SYSCALL_ERRNO (res, err) == EINVAL)
  41. p = extend_alloca (p, psize, 2 * psize);
  42. if (res == 0 || INTERNAL_SYSCALL_ERROR_P (res, err)) {
  43. __set_errno (INTERNAL_SYSCALL_ERRNO (res, err));
  44. return -1;
  45. }
  46. __kernel_cpumask_size = res;
  47. }
  48. /* We now know the size of the kernel cpumask_t. Make sure the user
  49. does not request to set a bit beyond that. */
  50. for (cnt = __kernel_cpumask_size; cnt < cpusetsize; ++cnt)
  51. if (((char *) cpuset)[cnt] != '\0') {
  52. /* Found a nonzero byte. This means the user request cannot be
  53. fulfilled. */
  54. __set_errno (EINVAL);
  55. return -1;
  56. }
  57. return INLINE_SYSCALL (sched_setaffinity, 3, pid, cpusetsize, cpuset);
  58. }
  59. #else
  60. #define ___HAVE_NO_sched_setaffinity
  61. #endif
  62. #if defined ___HAVE_NO_sched_setaffinity && defined __UCLIBC_HAS_STUBS__
  63. int sched_setaffinity(pid_t pid, size_t cpusetsize, const cpu_set_t *cpuset)
  64. {
  65. __set_errno(ENOSYS);
  66. return -1;
  67. }
  68. #endif
  69. #endif /* __USE_GNU */